Assessment fire hazard

Probably the best way of assessing fire hazard is by calculations via mathematical fire growth and transport models, such as HAZARD I [58], FAST [59], HARVARD [60] or OSU [61]. These models predict times to reach untenable situations. They are often combined with fire escape models and will, then, yield times to escape. 

Fire safety in a particular scenario is improved by decreasing the corresponding level of fire risk or of fire hazard. Technical studies will, more commonly, address fire hazard assessment. Fire hazard is the result of a combination of several fire properties, including ignitability, flammability, flame spread, amount of heat released, rate of heat release, smoke obscuration and smoke toxicity. 

To develop standards for assessing fire hazard and for providing fire safety in buildings". 

We have an opportunity to shape and mold the future, and to benefit society by our struggle with assessing fire hazard. It is a challenge the urethane industry has already begun to meet. 

Flash Point. The flash point of a liquid is a measure of the flammability of its vapors on application of an external flame. It is used to assess fire hazards. The flash point of paints may have to be measured to comply with legal requirements relating to the storage, transportation, and use of flammable products. According to ISO 1523, the flash point (closed cup) is the minimum temperature to which a product, confined in a closed cup, must be heated for the vapors emitted to ignite momentarily in the presence of a flame, when operated under standard conditions. 

Here too, the criteria for evaluating the fire resistance of liquid dielectrics are changing drastically because of a new awareness of the need to assess fire hazards as objectively as possible. 

The first major hazard in process plants is fire, which is usually regarded as having a disaster potential lower than both explosion or toxic release. However, fire is still a major hazard and can, under the worst conditions, approach explosion in its disaster potential. It may, for example, give rise to toxic fumes. Let us start by examining the important factors in assessing fire as a hazard. 

The assessment of the contribution of a product to the fire severity and the resulting hazard to people and property combines appropriate product flammabihty data, descriptions of the building and occupants, and computer software that includes the dynamics and chemistry of fires. This type of assessment offers benefits not available from stand-alone test methods quantitative appraisal of the incremental impact on fire safety of changes in a product appraisal of the use of a given material in a number of products and appraisal of the differing impacts of a product in different buildings and occupancies. One method, HAZARD I (11), has been used to determine that several commonly used fire-retardant—polymer systems reduced the overall fire hazard compared to similar nonfire retarded formulations (12). 

Metal deck assembhes are tested by UL for under-deck fire hazard by usiag their steiaer tunnel (ASTM E84). The assembly, exposed to an under-deck gas flame, must not allow rapid propagation of the fire down the length of the tuimel. FM uses a calorimeter fire-test chamber to evaluate the hazard of an under-deck fire. The deck is exposed to a gas flame and the rate of heat release is measured and correlated to the rate of flame propagation. A different FM test assesses the damage to roof iasulations exposed to radiant heat. 

HS(G)64 Assessment of fire hazards from solid matenals and the precautions required for their safe storage... 

Flammability. The fire hazard associated with plastics has always been difficult to assess and numerous tests have been devised which attempt to grade materials as regards flammability by standard small scale methods under controlled but necessarily artificial conditions. Descriptions of plastics as selfextinguishing, slow burning, fire retardant etc. have been employed to describe their behaviour under such standard test conditions, but could never be regarded as predictions of the performance of the material in real fire situations, the nature and scale of which can vary so much. 

The potential for fire hazards is rather liigh in tlie chemical industry. However, tliis potential is generally judged to be less tlicui that of an explosion or toxic release, as discussed later. The scale of a fire hazard can be deteniiined by assessing the following factors, ... 

Break gallery. An experimental installation to assess the hazards of firing explosives in coal mines in the presence of breaks (see p.80). 

Hartzell, G.E. Emmons, H.W. "The Fractional Effective Dose Model for Assessment of Hazards Due to Smoke from Materials," J. Fire Sciences 1988, 6(5), 356-362. 

Some of the other properties of interest for fire hazard assessment cannot be measured with RHR calorimeters. They include flame spread, limiting oxygen index (LOI, or simply oxygen index, 01 both names have been used, but the author s preferred nomenclature is the one used here) and fire endurance. 

Fire risk assessment is made in order to determine the overall value of decreasing fire hazard in a particular scenario. The level of fire risk that is acceptable for a situation is, normally, a societal, and not a technical, decision. Therefore, fire hazard assessments are generally more common than fire risk assessments. The NFPA Research Foundation has undertaken a project to develop a methodology for fire risk assessment. It has done this by studying four cases in detail upholstered furniture in residential environments, wire and cable in concealed spaces in hotels and motels, floor coverings in offices and wall coverings in restaurants. 

Toxic potency of smoke data can be used as one of the inputs in fire hazard assessment. In particular, they can be combined with average mass loss rates and times to ignition to obtain a quick estimate of toxic fire hazard. 

The traditional way of measuring fire properties is to determine each property individually by carrying out small scale tests on materials, in isolation of the fire scenario of interest. A crude means of fire hazard assessment would then be to establish minimal "passing" standards for each test and require all materials to meet them. 

The incident flux used in the NBS smoke chamber is only a single value, at 2.5 w/cm2, which is a relatively mild flux for a fire, and cannot, thus represent all the facets of a fire. The light source is polychromatic, which causes problems of soot deposits and optics cleaning, as compared to measurements done using a monochromatic (laser) beam. Finally, the units of the normal output of this smoke chamber are fairly arbitrary and the data is of little use in fire hazard assessment. 

The NBS Cone calorimeter has been shown to be more versatile than the OSU calorimeter and to allow simultaneous measurements of a large variety of the properties required for a full assessment of fire hazard in real fires. Furthermore, it can be used to calculate combined properties, including those involving mass loss, which are much more useful as indicators of fire hazard than any individual one. 

Hazard quotient (HQ), 25 238 Hazards. See also Fire hazards Radiation hazards Safety entries assessments of, 27 839, 846 of ethylene-propylene polymers, 10 716 of hydrogen peroxide, 14 61-63 oxygen-related, 17 760-761 penalties for, 73 155-156 recognition in industrial hygiene, 74 205-213... 

Key words Landfill fire, hazard assessment, risk assessment, Hawaii community... 

Combustion gases Regulatory applications. Fire hazard assessment Composition monitoring - gas Trace gas and vapor analysis... 

Understanding fire hazards is essential to risk reduction and fire protection decision-making. A fire hazard analysis (FHA) is a tool used to understand fire hazards. The process of quantifying the fire hazard is typically motivated by the need to determine the overall hazard of a process or facility or to have a decision-making tool for fire protection systems (Chapter 6). An FHA is an important element of a risk assessment and can also be used as a stand-alone hazard evaluation tool. 

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